Defroster for freezing coils



y 1956 E. R. JACKSON 2,755,371

DEFROSTER FOR FREEZING COILS Filed March 20. 1953 EARL R. J/ICKSON.

IN VEN TOR.

Wm; M.

ATTORNEY:

DEFROSTER FOR FREEZING COILS Earl R. Jackson, Baltimore, Md.

Application March 20, 1953, Serial No. 343,726

1 Claim. (Cl. 219-19) This invention relates to defrosting devices for refrigerators, deep freezers and cooling systems and more particularly to a method and apparatus particularly adapted for use in preventing heavy accumulations of ice and frost from forming on the freezer coils and decreasing their cooling efiiciency.

The general practice heretofore used in defrosting the freezing compartment of various units has been to raise the temperature within the enclosure by positioning external heating units in the spacing between the freezing coils, or by blowing hot air against the freezing coils to melt the ice or frost therefrom.

An important object of this invention is the provision of a defrosting device that will quickly and efliciently free the cooling coils of ice.

Another object of this invention is the provision of a defrosting device that will expeditiously defrost the cooling unit with Very little rise in temperature in its enclosure.

Another object of the invention is to provide a series of freezing coils having closed end tubes preferably in serted at a predetermined number of bends in the freezing coils to receive interchangeable heating units to quickly increase the temperature of the freezing medium contained in the coils Without changing the temperature of the freezing medium in the system other than in the freezing coils.

Other objects of the invention will become apparent as the invention is more fully set forth.

For a clearer understanding of the invention and its objects, reference is made to the accompanying drawing, wherein a particular form of the invention is disclosed. This drawing when used in conjunction with the following description illustrates such form by way of example, while the claim emphasizes the scope of the invention.

The single figure of the drawing represents a side elevation of a freezing coil unit embodying this invention, with parts broken away to show the method of mounting the heating units therein.

Similar reference numerals refer to similar objects throughout the drawing.

In the construction shown in the drawing a freezing unit 10 is formed of tubing or the like 11 provided with holes 12 at predetermined bends to receive heat unit closures 14 to enclose the heating units 15 and prevent the heaters from coming into direct contact with the freezing medium 17. This allows the heaters to be replaced when necessary without draining the freezing medium from the system. Each closure 14 is closed at one end, and open at the other end to receive the heater, and is welded at 19 to provide a leakproof joint between the closure 14 and the bends 13. The heating units are connected into an electrical circuit 18 and are automatically turned off and on at predetermined intervals by the use of any of the conventional time or temperature controlled electric switches that can be used to stop the circulation of the refrigerant and turn on the heaters to raise the temperature of the freezing medium in the freezing unit or coils 10 at predetermined intervals without appreciably raising the temperature of the freezing medium in the rest of the system, this enables the system to be defrosted more quickly when using this invention.

While but one general form of the invention is shown in the drawing and described in the specification, it is not desired to limit this application for patent to this particular form as it is appreciated that other forms of construction could be made that would use the same principles and come within the scope of the appended claim.

Having thus described the invention, what is claimed is:

In a refrigeration system of the dry expansion type, an evaporator comprising a plurality of parallel straight sections, a plurality of U-shaped sections each associated with two straight sections of one of said pairs for connecting said sections to each other, an enclosing element projecting from the exterior of certain of said U-shaped sections into one of the straight sections associated therewith, an electric heating element removably positioned in each of said enclosing elements and means forming with said heating elements an electric circuit whereby refrigerant in all of the portions of said evaporator may be subjected to a heating influence to melt from the evaporator frost and ice formed thereon.

References Cited in the file of this patent UNITED STATES PATENTS 1,676,068 Bayer July 3, 1928 1,731,058 Pierson Oct. 8, 1929 1,764,139 Alex June 17, 1930 2,001,323 Dick May 14, 1935 

